Molecular Scanning and Morpho-Physiological Dissection of Component Mechanism in Lens Species in Response to Aluminium Stress

Abstract

Aluminium (Al) stress was imposed on 285 lentil genotypes at seedling stage under hydroponics to study its effects on morpho-physiological traits where resistant cultigens and wilds showed minimum reduction in root and shoot length and maximum root re-growth (RRG) after staining. Molecular assortment based on 46 simple sequence repeat (SSR) markers clustered the genotypes into 11 groups, where wilds were separated from the cultigens. Genetic diversity and polymorphism information content (PIC) varied between 0.148–0.775 and 0.140–0.739, respectively. Breeding lines which were found to be most resistant (L-7903, L-4602); sensitive cultivars (BM-4, L-4147) and wilds ILWL-185 (resistant), ILWL-436 (sensitive) were grouped into different clusters. These genotypes were also separated on the basis of population structure and Jaccard’s similarity index and analysed to study Al resistance mechanism through determination of different attributes like localization of Al and callose, lipid peroxidation, secretion of organic acids and production of antioxidant enzymes. In contrast to sensitive genotypes, in resistant ones most of the Al was localized in the epidermal cells, where its movement to apoplastic region was restricted due to release of citrate and malate. Under acidic field conditions, resistant genotypes produced maximum seed yield/plant as compared to sensitive genotypes at two different locations i.e. Imphal, Manipur, India and Basar, Arunanchal Pradesh, India during 2012–13, 2013–14 and 2014–15. These findings suggest that Al stress adaptation in lentil is through exclusion mechanism and hybridization between the contrasting genotypes from distinct clusters can help in development of resistant varieties.

WITHDRAWN: Deep expression scrutiny provides genetic basis of aluminium tolerance in wild (Lens nigrican) and cultivated lentil (Lens culinaris Medik.)

“…APX is one of the highly regulated enzymes [88]. In our previous studies also, we have identified significant increase in GPX activity in wild lentil genotypes [7]. For organic acids synthesis pathway, several genes were significantly up-regulated in wild genotype, one being that of Aconitatehydratase (Aco).…”

“…Three divergent lentil genotypes viz. L-4602, Barimasur-4 (BM-4) and ILWL-15 were used in this study [7]. First two accessions belong to Lens culinaris, whereas third belongs to Lens nigrican.…”

“…These accessions were chosen based on previous studies, where L-4602 was found to be Al tolerant breeding line developed at Indian Agricultural Research Institute (IARI), India whereas BM-4 was found to be Al sensitive cultivar, which was developed from the cross between ILL-5888 (improved landrace) and ILL-5782 (breeding line) at International Center for Agricultural Research in the Dry Areas (ICARDA), Syria [7,90,91]. ILWL-15 is a mineral rich wild accession which was originated in France and was reported to be moderately tolerant to Al stress [7,92].…”

“…(2016) with minor modifications at National Phytotron Facility, IARI, India [7]. Seedlings emerged in hydroponic medium were placed in growth chamber that was programmed for relative humidity (%) and temperature of 55.…”

Deep expression scrutiny of juxtaposed wild and cultivated lentil furnishes new insight into aluminium tolerance mechanism

“…Thereby, to develop Al stress tolerant cultivars, an in depth understanding of divergent resistance mechanisms operating in lentil is crucial. Initial effort towards understanding these mechanisms in Lens species has revealed pattern II exclusion mechanism as one of the components, where secretion of citrate and malate from roots were observed which prevented binding of Al to extracellular and intracellular substances of the roots [7,8]. Further, secretion of exudates was found to be highest in wild genotypes [7].…”